Originally Posted by
DOUBLE BOGEY
Given the short flight time, fire trailing and persistent and the pilot reporting and engine failure.....maybe a turbine burst (looking like engine failure with zero Tq/Nf), That savages the tail boom flange area with shrapnel. Meanwhile the Gas Generator is still working and the FADEC response to Zero NF is to open the fuel to max chat. The fire escaping from the compromised combustion chamber finishes the job. I have no idea why the pilot did not have a fire warning or if he missed this in the mix of confusing indications.
With an engine fully failed (ie all parts stop rotating) the fuel pressure becomes zero everywhere in that firewall box and the chances of a persistent fire almost zero. Maybe!
DB
Worth noting that for the T1, the engine overspeed protection system was optional so if he did suffer a fault which led to a runaway up, the engine may not have automatically shutdown (and event which has happened on a T1 albeit during start when the pilot started before the FADEC had fully booted).
As mentioned before, all 3 occasions in the ASN history of EC135 incidents where there has been an in flight engine fire have all been after engine overspeed events (all on P1 thus far due to inadvertant entry into manual).